The fire started about 7 a.m. Thursday and has burned across the Camarillo landscape, scorching brush between the Camarillo Springs neighborhood to the north and more homes to the south. The Santa Ana winds are blowing the flames southwest toward Cal State Channel Islands and Pacific Coast Highway.

An unknown number of recreational vehicles have been destroyed and some homes have been damaged, Nash said. There are no reported injuries.

The winds are expected to last through the night and down Friday morning.

Hundreds of firefighters have made some progress on the flank of the wind-driven fire, Ventura County Fire Department spokesman Bill Nash said. But the blaze remained uncontained because crews have been unable to get in front of it, he said.

Helicopters are now being used in the attack.

Television footage showed numerous motor homes burning in a parking lot along with some type of agricultural building.

Firefighters are focused on protecting hundreds of homes as the Springs fire moves toward Newbury Park and the Camarillo Springs area, Ventura County Fire Department spokesman Tom Kruschke said. But officials are also preparing in case the blaze moves toward Pacific Coast Highway -- a possibility within "the potential of the fire," Kruschke said.

But with strong Santa Ana winds, low humidity and high temperatures -- not to mention the amount of fuel in the area -- Kruschke said it was hard to say where the flames might go.

"It's very unpredictable. Winds are swirling and twisting, and we don't know what way it's going to turn," he said. "We're kind of at Mother Nature's mercy at this point."

Evacuations were ordered for the Dos Vientos neighborhood of Newbury Park, the Camarillo Springs area of Camarillo, Cal State Channel Islands and the area south of Potrero Road to Pacific Coast Highway.

Newbury Park High School evacuated its campus shortly after 10:30 a.m. Thursday, citing air quality as the primary factor. While the fire was still burning far away from campus, a large number of students either did not show up or were picked up by their parents because of the fire, leading school authorities to shutter classes for the day.